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author | Kartik K. Agaram <vc@akkartik.com> | 2021-03-03 22:09:50 -0800 |
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committer | Kartik K. Agaram <vc@akkartik.com> | 2021-03-03 22:21:03 -0800 |
commit | 71e4f3812982dba2efb471283d310224e8db363e (patch) | |
tree | ea111a1acb8b8845dbda39c0e1b4bac1d198143b /linux/advent2020/1b.mu | |
parent | c6b928be29ac8cdb4e4d6e1eaa20420ff03e5a4c (diff) | |
download | mu-71e4f3812982dba2efb471283d310224e8db363e.tar.gz |
7842 - new directory organization
Baremetal is now the default build target and therefore has its sources at the top-level. Baremetal programs build using the phase-2 Mu toolchain that requires a Linux kernel. This phase-2 codebase which used to be at the top-level is now under the linux/ directory. Finally, the phase-2 toolchain, while self-hosting, has a way to bootstrap from a C implementation, which is now stored in linux/bootstrap. The bootstrap C implementation uses some literate programming tools that are now in linux/bootstrap/tools. So the whole thing has gotten inverted. Each directory should build one artifact and include the main sources (along with standard library). Tools used for building it are relegated to sub-directories, even though those tools are often useful in their own right, and have had lots of interesting programs written using them. A couple of things have gotten dropped in this process: - I had old ways to run on just a Linux kernel, or with a Soso kernel. No more. - I had some old tooling for running a single test at the cursor. I haven't used that lately. Maybe I'll bring it back one day. The reorg isn't done yet. Still to do: - redo documentation everywhere. All the README files, all other markdown, particularly vocabulary.md. - clean up how-to-run comments at the start of programs everywhere - rethink what to do with the html/ directory. Do we even want to keep supporting it? In spite of these shortcomings, all the scripts at the top-level, linux/ and linux/bootstrap are working. The names of the scripts also feel reasonable. This is a good milestone to take stock at.
Diffstat (limited to 'linux/advent2020/1b.mu')
-rw-r--r-- | linux/advent2020/1b.mu | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/linux/advent2020/1b.mu b/linux/advent2020/1b.mu new file mode 100644 index 00000000..a638d228 --- /dev/null +++ b/linux/advent2020/1b.mu @@ -0,0 +1,113 @@ +# https://adventofcode.com/2020/day/1 +# +# To run (on Linux): +# $ git clone https://github.com/akkartik/mu +# $ cd mu +# $ ./translate_mu apps/advent2020/1b.mu +# $ ./a.elf < input +# found +# 143 407 1470 +# 85555470 +# +# You'll need to register to download the 'input' file for yourself. + +fn main -> _/ebx: int { + # data structure + var numbers-storage: (array int 0x100) # 256 ints + var numbers/esi: (addr array int) <- address numbers-storage + var numbers-index/ecx: int <- copy 0 + # phase 1: parse each line from stdin and add it to numbers + { + var line-storage: (stream byte 0x100) # 256 bytes + var line/edx: (addr stream byte) <- address line-storage + { +#? print-string 0, "== iter\n" + # read line from stdin + clear-stream line + read-line-from-real-keyboard line + # if line is empty (not even a newline), quit + var done?/eax: boolean <- stream-empty? line + compare done?, 0/false + break-if-!= +#? print-stream-to-real-screen line + # convert line to int and append it to numbers + var n/eax: int <- parse-decimal-int-from-stream line +#? print-int32-decimal 0, n +#? print-string 0, "\n" + var dest/ebx: (addr int) <- index numbers, numbers-index + copy-to *dest, n + numbers-index <- increment +#? print-string 0, "== " +#? print-int32-decimal 0, numbers-index +#? print-string 0, "\n" + loop + } + } + # phase 2: for every pair of distinct numbers, check if the rest of the + # array has 2020-it + var i/edi: int <- copy 0 + { + compare i, numbers-index + break-if->= + # for j from i+1 to end + var j/edx: int <- copy i + j <- increment + { + compare j, numbers-index + break-if->= + { + compare i, j + break-if-= + var target/ebx: int <- copy 0x7e4 # 2020 + var src/edi: (addr int) <- index numbers, i + target <- subtract *src + var src2/ecx: (addr int) <- index numbers, j + target <- subtract *src2 + { + var found?/eax: boolean <- find-after numbers, j, target + compare found?, 0/false + break-if-= + print-string 0, "found\n" + print-int32-decimal 0, *src + print-string 0, " " + print-int32-decimal 0, *src2 + print-string 0, " " + print-int32-decimal 0, target + print-string 0, "\n" + target <- multiply *src + target <- multiply *src2 + print-int32-decimal 0, target + print-string 0, "\n" + return 0/success + } + } + j <- increment + loop + } + i <- increment + loop + } + return 1/not-found +} + +fn find-after _numbers: (addr array int), start: int, _target: int -> _/eax: boolean { + var numbers/esi: (addr array int) <- copy _numbers + var target/edi: int <- copy _target + var len/ecx: int <- length numbers + var i/eax: int <- copy start + i <- increment + { + compare i, len + break-if->= + var src/edx: (addr int) <- index numbers, i + # if *src == target, return true + compare *src, target + { + break-if-!= + return 1/true + } + i <- increment + loop + } + return 0/false +} |